P0300 on a 2020 Ford Edge
P0300 is a generic OBD2 powertrain code for random or multiple cylinder misfire. Unlike P0301 through P0308, it does not point to one specific cylinder, so the cause can be ignition, fuel, air, sensor, or mechanical.
Not your vehicle? See general P0300 info.
Most common causes on the 2020 Ford Edge
Ranked from 298 NHTSA owner complaints filed for this vehicle.
- 1
Worn spark plugs
Low severityOne owner in this batch had spark plugs replaced after hesitation, choking, and stalling, with the failure recurring; check gap/fouling and replace on schedule.
Reported in 1 NHTSA complaintParts:spark plugs - 2
Coolant intrusion into a cylinder from a failing head gasket
High severityA shop in this batch diagnosed a blown head gasket with coolant entering the engine; coolant entering a cylinder fouls combustion and causes a dead-cylinder misfire.
Reported in 1 NHTSA complaint - 3
Failing ignition coil(s)
Medium severityA cracked or weak coil-on-plug misfires one cylinder, often worse under load or when hot; swap coils to isolate.
Common causeParts:ignition coil - 4
Clogged or leaking fuel injector
Medium severityAn injector delivering too little or too much fuel unbalances one cylinder; check injector flow/balance test.
Common causeParts:fuel injector - 5
Vacuum/intake leak
Medium severityUnmetered air past the MAF leans a cylinder or bank enough to misfire under light load/idle; smoke-test the intake.
Common cause - 6
Carbon-fouled intake valves
Low severityDirect-injection engines accumulate carbon on the backs of intake valves, disrupting airflow evenly enough to trigger a random misfire code.
Common cause - 7
Low compression (worn rings/valves)
High severityInternal wear reduces cylinder sealing and combustion efficiency; a compression or leak-down test isolates the affected cylinder.
Common cause
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These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0300 on your car still needs shop confirmation before any repair.
Common symptoms
- Flashing or steady check engine light
- Rough idle
- Shaking under acceleration
- Loss of power
- Fuel smell from exhaust
What to check before replacing parts
Scan for cylinder-specific misfire codes
Look for: A companion P0301–P0308 pins the misfire to one cylinder — start there. P0300 with no cylinder code points at something hitting several at once: fuel pressure, a large vacuum leak, or timing.
Inspect the spark plugs and coils
Look for: Pull the plugs: black/sooty = rich, oily = oil intrusion, white/blistered = lean or overheating, cracked porcelain or an out-of-spec gap = replace. Then swap a coil to another cylinder — if a cylinder-specific code follows the coil, the coil is bad.
Check fuel trims for a vacuum leak
Look for: High positive short- and long-term trims (worst at idle, improving as RPM rises) mean unmetered air is getting in. Smoke-test the intake and listen for hissing.
Verify fuel pressure
Look for: Compare running/cranking pressure to the vehicle spec. Low or dropping pressure starves multiple cylinders and reads as a random misfire — suspect the pump, filter, or regulator.
Compression / leak-down test if ignition and fuel check out
Look for: A cylinder 15%+ below the others, or leak-down hissing from the intake (intake valve), exhaust (exhaust valve), or oil filler (rings), means the misfire is mechanical — not a swap-in part.
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